Control and knowledge of the amount of contamination in hydraulic fluids utilized in such things as industrial, vehicular and machine hydraulic systems is of importance, and often of critical importance, to the proper functioning of the system and components therein. In addition to the problem of particulate contamination is the adverse effect resulting from the presence of air in the system fluid of high pressure hydraulic systems in particular. The detrimental effects of high air ratio levels are well-known, and include sluggish response, noisy operation, loss of power, pump cavitation, decreased component life, and erroneous performance evaluations. No prior art means is known for measuring air-liquid volume ratios because of the difficulty of measuring the volume of air in hydraulic fluid under different operating conditions. Without some means of assessing air-liquid volume ratios it is difficult to establish an acceptable air ratio level ralative to system performance and component lift.
In carrying out the method of this invention I utilize the improved apparatus of my co-pending application Ser. No. 899,662, entitled "Apparatus For Counting Particle Contamination Of Liquid," filed Apr. 24, 1978.
Various methods for measuring air in hydraulic fluid are discussed in "The BFPR JOURNAL", 1978, 11, 3, 275-281, in an article entitled "Air In Oil-Available Measurement Methods." Also, U.S. Pat. No. 3,952,580, granted Apr. 27, 1976, represents known prior art for counting particulate contamination in a liquid.
As is well-known, entrained air is in the form of discreet bubbles which are held in the body of a fluid whereas dissolved air is in solution with the fluid. For any given hydraulic fluid under any operating conditions my improved method can be utilized to accurately determine the entrained air-liquid volume ratio.